figure



Nov. 14, 1961 R. A. STEARN REAR GATE BOAT HOIST Original Filed April 16,1956 4 Sheets-Sheet 1 INVENTOR.

Nov. 14, 1961 R. A. STEARN REAR GATE BOAT HOIST 4 Sheet s-Sheet 2Original Filed April 16, 1956 INVENTOR.

Ma! Q .Jfiwz/ Nov. 14, 1961 R. A. STEARN REAR cm: BOAT noxs'r OriginalFiled April 16, 1956 4 Sheets-Sheet 3 Nov. 14, 1961 R. A. STEARN REARGATE BOAT HOIST Original Filed April 16, 1956 4 Sheets-Sheet 4 INVENTOR.

Ml/ BY United States Patent 25,081 REAR GATE BOAT HOIST Richard A.Steam, Sturgeon Bay, Wis., assignor, by mesne assignments, to DrottManufacturing Corporation;

Milwaukee, Wis., a corporation of Wisconsin Original No. 2,889,061,dated June 2, 1959, Scr. No.

578,490, Apr. 16, 1956. Application for reissue May 24, 1961, Ser. No.116,232

12 Claims. (Cl. 214-394;)

Matter enclosed in heavy brackets II] appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

This invention relates to a boat hoist of the gantry type described byapplicant in his copending patent application Serial No. 557,371 filedJanuary 4, 1956. More particularly, it relates to a boat hoist which hasan openable rear gate.

In applicants copending application, his concept of a flat U-shaped baseframe carrying upwardly extending gantries which support the slingsopened a possiblity for boat hoists which does not exist in the case ofexisting parallelepiped frame boat hoists. Boat hoists have never beenwidely used because they can handle only a few of the boats found in theaverage yard. Particularly, they cannot be used for sailboats unless themasts have been removed. The mast prevents the sailboat from enteringthe main body of the hoist. The concept of the fixed tail gantry and ofthe spaced and movable forward gantry with the entire center of thehoist upwardly open suggested the idea of opening the rear gantry toadmit a sailboat into the body of the boat hoist and then closing itbefore actually raising the boat. By opening such a gate, one couldfloat a sailboat into the boat hoist without removing the mast oraltering the rigging. In order to close the gate, it might be necessaryto remove the rigging.

The problem presented by the rigging is illustrated in schematicFIGURE 1. The numeral 1 identifies the slip filled with water. One pierbears the numeral 2. The ground level is at 3. A sailboat 4 has a mast 5and its sails are down. The mast is supported by guy wires. Dependingfrom the top of the mast 5' is a cable 15 which holds the boom 17 at itsouter end. Assuming that the line 6 represents the maximum draft of theboat, and that the distance from 6 to the ground level 3 is three feet,in order to clear the keel, which is shown in the retracted position, byone foot above the ground level, it is necessary to raise the boat fourfeet. If the boat hoist is thirty feet long, that is, thirty feetbetween the wheel 7 and the fifth wheel on the tractor 8, and the crossmember 11 of the forward gantry is at its farthest position forward,then the boat hoist cannot be used to raise the boat even though theboat with rigging in place can be positioned between the two crossmembers of the gantry. The distance 13 is substantially less than therequired four feet.

In the disclosure that follows, applicant shows a transversely movabletail gate and suggests a pivoted gate. The latter is pivoted at the topof an upright at the rear corner of he boat hoist. This pivoted orhinged gate can be closed and fastened to the top of the upright on theother rear corner of a boat hoist that functions similarly to the onethat is shown in copending application Serial No. 557,371. This pivotedgate is suggested in FIGURE 1 swinging upwardly as 21 or horizontally as23. Its use is impaired, however, because it is difiicult to close thegate so that it occupies the closed position of FIGURE 2, withoutloosening the rigging to avoid fouling.

A preferred gate is shown in FIGURES 4 to 12. This preferred tail gateis not hinged, but is a sliding bar which is movable horizontally in aline at right angles to' the length of the boat hoist between the topsof the two rear uprights. In closed position, it forms the tail gantry.In open position, it extends at right angles to the vertical support andpermits a boats mast and rigging to enter the boat hoist. It will beappreciated that if the boat is not longer than the hoist, the riggingneed not be touched. Where the boat is longer, one advances the boatinto the hoist until an opening in the rigging is in transversealignment with the sliding bar. The opening through the rigging mustextend downwardly sufiiciently so that the boat may be raised. Thisfeature is of great value to the shipyard owner because he is notobliged to wait on the convenience of sportsmen to take down the riggingbefore the boat is put in a cradle on land.

The advantage of the sliding bar gate is evident from examining the sameboat in the same slip in FIGURE 2. Here, the boat hoist has not beenbacked quite so far out on the pier, with the result that the slidingbar 9 is at a level below the cable 15. Since the space between thecable 15 and the boom 17 and the mast 5 is open, the sail being down,the cross bar can be moved across the space forming the tail gantry andthe boat raised out of the water. The boat is shown in raised positionin FIGURE 3, and the hoist may now be moved.

In addition to the operational advantage possessed by the sliding bargate, improved rigidity of the entire rear portion of the frame isobtained because as the disclosure hereinafter shows, a feature of theinvention is the movement of the end of the gate into a socket whichengages all walls of the end of the gate on all sides. This provides arigidity which is not as simply obtainable where a gate that swings intoposition must be locked by bolts or other means.

Providing an openable tail gate on the gantry type boat hoist is theprincipal and sole object of this invention. However, in providingeither a swinging gate or sliding bar, applicant encountered a number ofentirely new problems. So long as the transverse bar of a tail gantry issupported by both uprights of the U-shaped frame, torque around the mainaxes of the I-beams or rails of the U-shaped frame arms is not great.When the transverse member is released from one side and supported onlyon the other side, the torque on these U-shaped frame arms issuflicient, particularly in the case of the 50-foot hoist, to twist it90. This torque can be produced not only by the side carrying the gate,but even the upright on the other side will slightly twist the beam.Comparatively small distortion makes it diflicult to unlatch the gateand impossible to close it.

Applicants first ancillary object is to prevent twisting of the framerails when the gate is open. This is effected by two features. First,and most importantly, is the substitution of a rectangular beam for theI-beam. As will appear in the disclosure that follows, this rectangularbeam is much more resistant to a twisting force around the axis of thebeam. Secondly, by rigidly clamping the bottom of the movable gantry toeach rectangular beam supporting it, the gantry acts as a truss whichlimits twisting of the tubular beam to points rearwardly of the pointwhere the movable gantry is locked to the tubular beams.

Another ancillary object of this invention is to provide a means forclamping and locking the transverse tail member rigidly to the top ofthe tail gantry uprights so as to provide a rigid gantry. While theforward gantry and the rectangular cross section beams are suflicient tohold the rear supports in upright position when the boat hoist isstanding vertically over the slip or the cradle, they are whollyinsufiicient to hold them vertically when load is applied to the rearsling or even to permit pulling the boat hoist around the yard unloaded.The rigidity of the rear gantry is very important. One of the featuresof the invention is the provision of a transversely mounted uprightI-beam which slides between rollers mounted on a rectangular tubemounted on one of the rear gantry uprights.

Another object of this invention is to so space the legs on each side ofthe forward movable gantry with respect to the weight of an I-beam usedas the two horizontal arms of the U-shaped frame that by locking the twospaced legs of the gantry to the I-beam, the laterally, and rearwardly,unsupported length of the I-beam is shortened, thereby enabling the useof a lighter I-beam than would otherwise be required.

These and such other objects as may hereinafter appear are attained inthe embodiments of the invention shown in the accompanying drawings,wherein:

FIGURES '1 to 3 are schematic views illustrating the function of atransversely movable tail gate on a boat hoist;

FIGURE 4 is a perspective view of applicants open gate boat hoist;

FIGURE 5 is an inside elevation of applicants openable gate rear gantry;

FIGURE '6 is a view taken on the line 6-6 of FIG- URE 5;

FIGURE 7 is a view taken on the line 77 of FIG- URE 5;

FIGURE 8 is a plan view of the latch keeper mounted on top of themovable gate;

FIGURE 9 is a view taken on the line 99 of FIG- URE 10, but partly cutaway;

FIGURE 10 is a side view, partly cut away, of the drum and leverassembly for operating the movable gate;

FIGURE 11 is an enlarged side elevation view of one of the assembliesfor locking the movable gantry to the rail;

FIGURE 12 is a view taken on the line 1212 of FIGURE 11;

FIGURE 13 is a perspective view of a portion of another boat hoist inwhich the rails are rectangular in cross section; and

FIGURE 14 is a sectional view taken on the line \14-- 14 of FIGURE 12.

Continuing to refer to the drawings, in FIGURE 4, the general appearanceof the rear gate boat hoist is the same as that of the trailer boathoist in copending application Serial No. 557,371, filed January 4,1956. A frame 10 has a U-shaped configuration, and comprises a base 11and elongated members or arms 12 and 14. A movable gantry 16 is mountedon the sleeves such as 18 which slip endwise over the rectangularhousing. This will be described in detail hereinafter.

The rear gantry, referring to FIGURES 5 and 6 consists of threesections, two uprights 20 and 22, and a transversely movable crossmember 24 which constitute the gate. The uprights such as 20 arefastened to the rectangular rails 12 or 14 and to the wheel assemblies27 and 29 by braces 26 and 28 and by gussets 26' and 28'. Mounted on thetop of upright 20 is a rectangular sleeve 30, and on the top of upright22 is an I-beam 32 having a socket.

Referring to the sleeve 30, fastened on its outside surface are fourpairs of arms or brackets such as 34 and 36, and between each pair aremounted rollers such as 38 and 40. Between these rollers is disposed theI-beam 0r transverse gate 24 so that it may slide horizontally. Mountedon the outside of the vertical upright 20 is a bracket 42 having arms 44and 46, see FIGURE 10. Between these arms is disposed a shaft 48carrying two cable drums 50 and 52. Adjacent the inside edge of thecable drum 50 is a ratchet 54, see also FIGURE 9, and adjacent theinside of the drum 52 is a ratchet 56, returning to FIGURE 10. Mountedcentrally of the shaft 48 is a lever arm 58 carrying a transverse pin 60upon one end of which is mounted a pawl 62- in engageable alignment withthe ratchet 56 and another pawl 64 in engageable alignment with theratchet 54. Referring to FIGURE 9, the pawl 64 is held in engagementwith the ratchet 54 by a spring 66 and by moving the pawl 64 past thedead center of the pin '60, the pawl 64 may be held out of engagementwith the ratchet. The same arrangement with spring exists for the pawl62. Referring to FIGURE 9, a pawl 68 may be dropped into the solid-lineposition and upon a counter-clockwise movement of the ratchet 54, drivenby the arm 58 and pawl 64, the pawl 68 will hold the ratchet at anyselected notched position. A ratchet similar to 68 but directed in theopposite direction, controls a reverse movement of the ratchet 56. Thepawl 68, referring to FIGURE 9, may be rendered inoperable by rotatingit slightly over 90. It is evident that by properly setting the pawls,the drums 50 and 52 may be positively rotated in either direction bymeans of the arm 58 and locked at any selected point.

Returning to FIGURE 5, mounted on each inside vertical wall of thesleeve 30 is a plate 70 which carries a U- shaped bracket 72, see FIGURE6, which in turn supports a shaft 74 upon which is disposed a sheave 76.

Mounted between the upper and lower bases of I-bearn 24 at the outer endis a plate 78 to which is fastened a spaced plate 80 which togethersupport the shaft 82 upon which is mounted a sheave 84. Disposed in anopening through the Web 86 of the I-beam 24 are a pair of plates 88which hold a shaft 90 on which is disposed a sheave 92. A sheave 94 ismounted on the inside wall of the sleeve 30, referring to FIGURE 6, asis the sheave 76. A cable 96, referring to FIGURE 5, is reeved over thedrum 50, see FIGURE 10, also, thence over the sheave 76, returning toFIGURE 5, over the sheave 84, and thence to the inside wall of thesleeve 30 to which it is tacked at 97. The cable 95 is reeled on drum52, see also FIGURE 10, and is reeved over the sheave 94, thence overthe sheave 92, and its end is fastened to the inside wall of the sleeve30 at 99. Referring to FIGURE 5, by

rotating the shaft 48 in a counter-clockwise direction, the cable 96 isreeled in, the cable 95 is unreeled, and the gate 24 is moved to theright. Conversely, by rotating the shaft '48 clockwise, the cable 95 isreeled in, the cable 96 is reeled out, and the gate 24 is pulled to theleft.

The end of the transverse member or gate 24 is tapered when viewed fromthe side or from the top, see FIGURES 5 and 6. It terminates in acylindrical member 100. Cut into the top flange 114 of the I-beam 86which constitutes the gate 24, and centered therein so that the webitself is cut away, is a hole in which seats a pipe section 104'whichwill receive a pin 124 vertically mounted on the end of the bar 122. Thepin 124 and the openended pipe section 104 cooperate as a latch andlatchkeeper.

Referring now to the upright 22 and the I-bearn 32 mounted thereon inFIGURE 5, the left-hand end of the web of the I-beam is cut away to thepoint 109 and is replaced with two plates 110 and 112 which slope towardeach other, referring to FIGURE 6, to form a V- configurationterminating with a V-apex at the web just beyond 109. The side edges ofthe top flange 114, referring to FIGURE 5, and the tapering bottomflange 116 of the gate 24 will nest against the side walls 110 and 112,referring to FIGURE 3, and the top of the flange 114 will engage theunder side of the plate 118 which in fact is the uncut-away portion ofthe base of the I-beam 32. For further rigidity and to limit theentrance of the wedge end of the gate 24, an inclined plate 119 ispostioned between the walls 110 and 112. 1

Mounted on the upper base 118, see FIGURE 5, is a open-ended housing 120parallel'with the length of the I-beam 32. Disposed in this open-endedhousing is a tubular rod 122 on the outer end of which is a pin 124which projects on both sides thereof and is adapted to engage plates 104and 106 of the keeper 102, see FIGURE 8. Guiding the rod 122 loosely inthe channel 120 is a plate 126 mounted on the rod 122. The outer end ofthe rod 122 is telescoped over a shaft 127 which fits loosely in anopening 129 in an end plate 131 mounted on the end of the I-beam 32. Theshaft 127 carries a pulley 128 threaded thereon. The outer end of theshaft 127 is slideably positioned in a bushing 130 mounted on a bracket132 which in turn is mounted on the end plate 131. A chain 134 isentrained over the pulley 128. A brass washer is positioned on the shaft127 on each side of the pulley 128. By working the pulley up against theplate 131, -it will retract the hollow rod 122 to the right. Conversely,by working the pulley against the bushing 130, the rod 122 can be forcedto the left.

The rod 122 must be movable for three or four inches. The trailer isnever moved excepting when the gate 24 is in locked position. When thetrailer is backed over a slip, however, there may be certain strainsimposed upon the locked and closed tail gate. In order to get the boatinto the slip, the gate must be open, and if there is an expansionstrain on the two uprights 20 and 22, the gate 24 will work somewhat outof alignment with the wedge socket 123.

Returning to FIGURES 4 and 5, mounted on the forward side of the sleeve30 is a bracket 140 which carries a pulley 142. Mounted on the upright22 is a shelf 144 upon which is positioned a shaft 146 carrying cabledrums 148 and 150. This shaft is driven through a gear box 152 by amotor, not shown, on the far side of the upright 22. The cable over thedrum 150 is reeved over the pulley 142 and thence around the pulley 154to an anchorage point 141 on the bracket 140. Reeled on the other drum148 is a cable 156 which is reeved over a pulley 158 and anchored to thesleeve 32. A sling 160 is suspended between two pulley assemblies 154and 158. In order to open the gate, it is necessary to disconnect thecable 162 and to hang both ends of the sling on the same upright, either20 or 22.

Normally, the gate 24 is in closed, locked position. The trailer hoistis not to be moved at any time with the gate open, nor the boat hoisted.Bending moments away from the vertical are imposed on the upright 20 themoment that the gate 24 ceases to be locked in the wedge recess 123. Theextent of these forces depends upon the degree of unbalance created bythe particular position of the gate 24 with respect to the upright 20.

The trailer hoist with the gantry 16 locked to the rails 12 and 14 andthe gate 24 locking the two uprights 20 and 22 together, is backed overthe slip as illustrated in FIGURE 1.

Returning to FIGURE 4, the cable 162 is disconected at the dead end at141 from the bracket 140, is slipped free of the pulley and the pulleyblock 154, is next lifted off the sheave 142, and dropped into thewater. At the time that the cable 162 is disconnected from the pulleyblock 154, referring to FIGURE 5, the latter with the sling 160 isrested in a holder 155 mounted near the lower part of the upright 20 sothat the sling will be under the boat as the boat is moved into theslip.

The next step is to operate the chain 134 so as to move the locking pin124 to the left as viewed in FIGURE 5. The entire drum assemblyindicated by the numeral 42 is placed in freely rotatable position, sothat the movement of pin 124 to the left pushes the movable gate 24through the pipe section 104 to the left. As this movement continues,the weight of the gate causes the end that is being freed to hangdownwardly increasingly as the surface 116 slides downwardly along thesurface 119. This continues until the pin 124 clears the pipe section104. When this happens, the operator completes the retraction of thegate by means of the lever 27 and cables 95 and 96. The boat is thenmoved into the slip. The cable 162 is then retrieved from the side ofthe slip adjacent the upright 22, reeved over the sheave 142, and

, thence over the sheave and the pulley block 154 to restore thearrangement shown in FIGURE 5.

The forward gantry may be released and moved forward to the bestposition for engaging the bow of the particular boat that is to beraised. Better practice, however, is to position and lock the forwardgantry longitudinally of the rails 12 and 14 before the rear gate isopened so that when that gate is open, the movable gantry will be usefulfor resisting twisting of the rear gantry uprights 20 and 22.

The boat is now moved into the slip until the positions shown in FIGURE1 or FIGURE 3 are attained. If all of the rigging is above the gate 24,as in FIGURE 1, there is no problem. If, on the other hand, there isintervening rigging, it is necessary to obtain a through verticalopening in the rigging extending from the lowermost point, referring toFIGURE 3, i.e., 164, to a distance slightly greater than the totalheight that the boat is to be raised, i.e., to a point such as 166. Thegate is thereupon closed by means of the handle 27, and locked by meansof the chain 134. Thereupon, the sling-lifting mechanism of bothgantries is started simultaneously and the boat raised to the positionshown in FIGURE 3.

THE MOVABLE GANTRY On the original 3- and 6-ton trailer hoists, such asthat disclosed in applicants copending application Serial No. 557,371,filed January 4, 1956, where the rear gantry was fixed, the forwardgantry performed the single function of raising one end of the boat.Locking it to the rails was solely to prevent longitudinal movement onthe rails. With the openable tail gate, applicant utilizes the forwardgantry as a truss to limit twisting of the rails.

Referring to FIGURE 4, the gantry is composed of a transverse beamsupported at each end by two I-beams 172, 174, 176 and 178. Each pair ofI-beams spreads outwardly in an inverted V-arrangement and their outsidesurfaces are spaced from each other by a distance slightly less than thespacing of the rails 12 and 14 so that their lower ends may bepositioned between these rails. Tacked to the outer surfaces of theI-beams, 176, for example, is an inverted charmel 180, see also FIGURE12. This channel joins the two beams 176 and 178 on one side thereof andis strengthened by I-beam segments 182 and 184 which act as gussets.

A pair of U-shaped channels 186 and 188 are spot welded in facingrelationship to form a tubular member, see also FIGURE 14. Its upper endis welded to the outer surface of the side wall of the inverted channeland to the outer bottom end of the gusset 184. Its lower end is held' inspaced relationship by a pair of links such as 190, one end of each ofwhich is bolted at 192 to the bottom of the associated I-beam such as176, referring to FIGURE 12, and its other end is bolted at 194 to thetubular member generally indicated by the numeral 196. A heavy duty nut198 is welded to the tubular member as shown in FIGURE 12 and in axialalignment with an opening 200.

Disposed in the nut 198 and the opening 200 is a heavy threaded shaft202 on the outer end of which is keyed by suitable means a hand wheel204. The other end 206 of the shaft 202 is reduced in diameter andbetween washers 208 and 210 is positioned a channel member 212, see bothFIGURE 12 and FIGURE 14. This channel member 212 isfree to rotate on theshaft 202, but it is maintained substantially in parallel relationshipto the tubular housing 196 because the side walls 214 and 216 embracethe housing 196 as can be seen in FIGURE 14. The flat surfaces of thechannel member 212 are immediately adjacent to the I-beam whichconstitutes the rail 12 of the frame. Mounted on the inner surface ofthe vertical member 176 is a plate 218 for engaging the adjacent edgesof the bases of the I-beam, complementary to the action of the flatsurface of the channel member 212. By turning the hand wheel 204counterclockwise as viewed in FIGURE 11, the channel member 212 will bemoved to the right as viewed in FIGURE 12, so that the assembly is nolonger locked to the I-beam 12.

The means for maintaining the spacing 220 in FIGURE 12 are rollers.Tacked to the outside wall and the inside wall of the channel members180 are plates such as 222 and 224, see FIGURE 4. One of these plates226 is shown in FIGURE 11. Mounted between the plate 226 and acorresponding plate, not shown, but on the far side, is a shaft 228which carries a roller 230 which is flanged on at least one side toengage the edge of the I-beam 12.

It is evident that by pulling up the hand wheel such as 204 tightly, theuprights such as 176, see FIGURE 12, will be locked to the two rails 12and 14 andthe gantry will act as a truss between them so as to limittwisting movement of the rails 12 and 14 to points rearwardly of theforward gantry, and where an I-beam is used to stabilize the beam.

The gantry is moved lengthwise of the rails 12 and 14 by means of acombination cable chain drive. Referring to FIGURE 4, the cable 230 isentrained over a sheave 232 and its ends are connected respectively to adrive chain 234 entrained over a sprocket 236. The drive chain beingmuch more expensive than the cable, has a length sufiicient to move thegantry back and forth along the rail for the selected distance. Asimilar combination cable and drive chain, sheave and sprocket aremounted on the outer side of the rail 14. The drive sprockets, such as236, are keyed to a shaft 238 which extends the width of the frame andcarries a crank 240 on the side adjacent the drivers seat.

In order to further reduce twisting at points rearwardly of the frontframe, applicant is now building frames in which the rails have arectangular cross section. This is illustrated in FIGURE 13 where therails 242 and 244 have rectangular cross sections. Circular crosssections have been considered, but they create certain problems inprovided a guideway for the movable gantry and in enabling one to lockthe gantries to them. The portion of a trailer boat hoist shown in thisFIGURE 13 is that of a small boat hoist. Here, the uprights of thegantry are mounted upon two inverted channel members 246 and 248.Between the under side of these channel members such as 246 and the topof the beam 242, are two or more rollers so that one may move the gantrylengthwise of the rails. In order to lock the gantry to the rails,applicant provides a simplified O-Shaped 'bail 250. The bail has twofacing end tongues such as 252 and 254 which are positioned on oppositesides of a leaf 246 on the outer side of the upright. A shaft 258 isappropriately threaded so that by turning the end 260 in one direction,the tongues are clamped to the leaf and also exert pressure on the sidesof the rail 242. The depending bracket 262 is fastened to the invertedchannel 246 and has a lower end portion which extends under the rail 242to prevent upsetting of the gantry where the trailer encounters unevenground or the like.

The two embodiments of the movable gantry shown in FIGURES 4 and 13 eachcarry a sling such as 264, referring to FIGURE 4. The sling has a pulleyblock at each end and a cable is reeved over each pulley, one end beingfixed to the gantry and the other being carried over one of the twodrums 266 and 268. Power is provided through a gear box 270 by a motor,not shown.

It will be appreciated that the horizontal gate is but one type of rearopening gate. It has advantages over a pivoted gate. A pivoted gate maybe of different types. One may consist of an elongated member pivotallymounted on a vertical axis at one end on the upright 20 and swingable tothe upright 22. Another type is also pivoted, but this time on ahorizontal axis so that it may be raised straight vertically. In eitherone of these cases, the bending moment imposed on the upright 20 is verygreat. One of the advantages of the transversely movable beam shown inthe application is that as it is retracted away from the upright 22, ittends to balance itself on top of the upright 20 and as it does so, itrelieves stress upon the arm 12 of the frame.

Applicants means for resisting bending moments caused by the upright 20are all interacting. When the gate is opened, the rigid locking of theforward gantry 16 t0 the arms 12 and 14 cause the forward gantry to actas a truss between the two arms. The portion of the beam rearwardly ofthe gantry is alone required to resist twisting. Further cooperating isthe use of bars of rectangular cross section.

When a boat is actually in the slings, it is, of course, of criticalimportance that the bar 122, caught in the latch 102, be tight. Theupper flat surface 114 of the tail gate 24 engages the under fiatsurface of the member 118, as well as the side Walls and 112 which formthe wedge recess. What applicant has attained is the substantialequivalent of a rectangular, parallelepiped frame without thelimitations of such frame.

Having thus described his invention, what he claims is:

l. A U-shaped boat hoist frame comprising a base member, an armextending rearwardly from each end of the base member so as to form ahorizontally disposed U-shaped frame, means for movably supporting saidframe horizontally above the ground, an inverted U- shaped gantry havingvertical members movably supported respectively on said arms, means forlocking the members to the arms so as to prevent twisting of the membersaround the arms under load, an upright near the free end of each arm, across member movably mounted near the top of one upright and having oneend engageable with the second upright so as .to span the two uprights,and means for locking the cross member to the second upright.

2. A U-shaped boat hoist frame comprising a base member, an armextending rearwardly from each end of the base member so as to form ahorizontally disposed U-shaped frame, means for movably supporting saidframe horizontally above the ground, an inverted U- shaped gantry havingvertical members movably supported respectively on said arms, means forlocking the members to the arms so as to prevent twisting of the membersaround the arms under load, an upright near the free end of each arm, across member disposed horizontally near the top of the first upright andmovable transversely of the upright so that one end may engage thesecond upright so as to span the two uprights, and means for lockingsaid end to the second upright.

3. The boat hoist frame of claim 2 wherein the arms of the frame have arectangular cross section.

4. A U-shaped boat hoist frame comprising a base member, an armextending rearwardly from each end of the base member so as to form ahorizontally disposed U-shaped frame, means for movably supporting saidframe horizontally above the ground, an inverted U- =shaped gantryhaving vertical members movably supported respectively on said arms,means for locking the members to the arms so as to prevent twisting ofthe members around the arms under load, an upright near the free end ofeach arm, rollers mounted near the top of one upright in a horizontalplane with their axes parallel to the arm-s of the frame, an elongatedmember slideable lengthwise on said rollers so that one end will engagethe second upright so as to span the two uprights, and means for lockingsaid end to the second upright.

5. The boat hoist frame of claim 4, wherein the end engageable with thesecond upright is tapering and the second upright has a mating socket toreceive it.

6. The boat hoist frame of claim 5, wherein the end engageable with thesecond upright is tapering and carries a latch keeper and the secondupright has -a mating socket to receive said tapering end and a latchfor positively drawing and holding the tapering end in the socket.

7. A U-shaped boat hoist frame comprising a base member, an armextending rearwardly from each end of the base'member, means for movablysupporting said frame horizon-tally above the ground, an inverted U-shape gantry having vertical members supported respecfively on saidarms, an upright near the free end of each arm, a cross member disposedhorizontally near the top of the first upright and movable transverselyof the upright so that one end may engage the second upright, means forlocking said end to the second upright, means including drums mounted onthe second upright for reeling cables, and an upwardly open sheavemounted on the first upright whereby when two cable ends are attached tothe ends of a sling, one cable may be entrained over the open sheavewithout disconnecting the sheave.

8. A boat hoist comprising a horizontally disposed, U-shaped frame,means for movably supporting said frame above the ground, an uprightmounted on the free end of each leg of the frame, a removable crossmember for connecting the upper ends of said uprights, an invertedU-shaped gantry having vertical members movably sup ported at theirlower ends respectively on the arms of the frame, and locking means onthe bottom of each leg of the movable gantry for clamping to each arm ofthe frame and preventing tortional' movement of the free end of the arm.

9. The boat hoist of claim 8 wherein the transverse member connectingthe upper ends of the upright is a movable gate and wherein each leg ofthe forward gantry contacts the associated arm of the base for asubstantial distance whereby the locking means holds the arm of theframe not only from tortional twisting but rigidly along the lengthconnected to the leg of the gantry.

10. A U-shaped boat hoist frame comprising first and second horizontallydisposed parallel arms forming a frame, means for movably supportingsaid frame horizontally above the ground, an inverted U-shaped gantryhaving vertical members movably supported respectively on said arms,means for locking the members to the arms so as to prevent twisting ofthe members around the arms under load, an upright near one end of eachof said arms, a cross-member movably mounted near the top of one uprightand having one end engageable with the second upright so as to span thetwo uprights, and means for locking the cross-member to the secondupright.

11. A boat hoist comprising first and second disposed parallel membersforming a frame, means for movably supporting said frame above theground, an upright mounted on one of the ends of each of said members, amovable cross-member for connecting the upper ends of said uprights, aninverted U-shaped gantry having vertical members movably supported attheir lower ends respectively on the members of the frame, and lockingmeans on the bottom of each leg of the movable gantry for clamping toeach member of the frame and preventing tortional movement of the freeend of the member.

12. A hoist comprising first and second horizontally disposed parallelmembers forming a frame, means for movably supporting said frame abovethe ground, an inverted U-shaped gantry having vertical legs supportedrespectively on adjacent ends of said members, first and second uprightsrespectively supported on said first and second members, a cross-memberdisposed horizontally near the top of the first upright and movabletransversely of the upright so that one end may engage the secondupright, means for locking said end to the second upright, meansincluding drums mounted on the second upright for reeling cables, and anupwardly open sheave mounted on the first upright whereby when two cableends are attached to the ends of a sling, one cable may be entrainedover the open sheave without disconnecting the sheave.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 505,638 Rasch Sept. 26, 1893 890,151 Marshall June9, 1908 1,543,686 Wengraf June 30, 1925 1,671,252 Moore May 29, 19282,099,078 Romine Nov. 16, 1937 2,424,899 Priester July 29, 19472,452,938 Krake Nov. 2, 1948 2,509,067 Leach May 23, 1950 2,644,545North July 7, 1953 2,750,197 Tripp June 12, 1956 FOREIGN PATENTS 470,114Great Britain Aug. 10, 1937

